1、bulk相当于数据库里的bash操作。
2、引入批量操作bulk，提高工作效率，你想啊，一批一批添加与一条一条添加，谁快?
3、bulk API可以帮助我们同时执行多个请求
4、bulk的格式：
action：index/create/update/delete
metadata：_index,_type,_id
request body：_source (删除操作不需要加request body)
{ action: { metadata }}
{ request body }
5、bulk里为什么不支持get呢？
答：批量操作，里面放get操作，没啥用！所以，官方也不支持。
6、create 和index的区别
如果数据存在，使用create操作失败，会提示文档已经存在，使用index则可以成功执行。
7、bulk一次最大处理多少数据量？
bulk会把将要处理的数据载入内存中，所以数据量是有限制的，最佳的数据量不是一个确定的数值，它取决于你的硬件，你的文档大小以及复杂性，你的索引以及搜索的负载。
一般建议是1000-5000个文档，如果你的文档很大，可以适当减少队列，大小建议是5-15MB，默认不能超过100M，可以在es的配置文件（即$ES_HOME下的config下的elasticsearch.yml）中。
elasticsearch-.yml（中文配置详解）来修改这个值http.max_content_length: 100mb【不建议修改，太大的话bulk也会慢】，
https://www.elastic.co/guide/en/elasticsearch/reference/2.4/modules-http.html
批量操作bulk例子
（1） 比如，我这里，在$ES_HOME里，新建一文件，命名为request。（这里为什么命名为request，去看官网就是）在Linux里，有无后缀没区别。
[hadoop@djt002 elasticsearch-2.4.3]$ pwd
/usr/local/elasticsearch/elasticsearch-2.4.3
[hadoop@djt002 elasticsearch-2.4.3]$ ll
total 56
drwxrwxr-x. 2 hadoop hadoop 4096 Feb 20 22:54 bin
drwxrwxr-x. 3 hadoop hadoop 4096 Feb 21 01:28 config
drwxrwxr-x. 3 hadoop hadoop 4096 Feb 20 22:59 data
drwxrwxr-x. 2 hadoop hadoop 4096 Feb 20 22:54 lib
-rw-rw-r--. 1 hadoop hadoop 11358 Aug 24 00:46 LICENSE.txt
drwxrwxr-x. 2 hadoop hadoop 4096 Feb 21 00:33 logs
drwxrwxr-x. 5 hadoop hadoop 4096 Dec 8 00:41 modules
-rw-rw-r--. 1 hadoop hadoop 150 Aug 24 00:46 NOTICE.txt
drwxrwxr-x. 2 hadoop hadoop 4096 Feb 20 22:59 plugins
-rw-rw-r--. 1 hadoop hadoop 8700 Aug 24 00:46 README.textile
[hadoop@djt002 elasticsearch-2.4.3]$ vim request
[hadoop@djt002 elasticsearch-2.4.3]$ more request
{"index":{"_index":"zhouls","_type":"emp","_id":"10"}}
{ "name":"jack", "age" :18}
{"index":{"_index":"zhouls","_type":"emp","_id":"11"}}
{"name":"tom", "age":27}
{"update":{"_index":"zhouls","_type":"emp", "_id":"2"}}
{"doc":{"age" :22}}
{"delete":{"_index":"zhouls","_type":"emp","_id":"1"}}
[hadoop@djt002 elasticsearch-2.4.3]$
或者
{ "index" : {"_index":"zhouls","_type":"emp","_id":"21"}}
{ "name" : "test21"}
例子：
{ "index" : { "_index" : "zhouls", "_type" : "type1", "_id" : "1" } }
{ "field1" : "value1" }
{ "index" : { "_index" : "zhouls", "_type" : "type1", "_id" : "2" } }
{ "field1" : "value1" }
{ "delete" : { "_index" : "zhouls", "_type" : "type1", "_id" : "2" } } (删除操作不需要加request body)
{ "create" : { "_index" : "zhouls", "_type" : "type1", "_id" : "3" } }
{ "field1" : "value3" }
{ "update" : {"_index" : "zhouls", "_type" : "type1","_id" : "1" } }
{ "doc" : {"field2" : "value2"} }
（2）使用文件的方式
vi requests
写入批量操作语句。比如，下面
{"index":{"_index":"zhouls","_type":"emp","_id":"10"}}
{ "name":"jack", "age" :18}
{"index":{"_index":"zhouls","_type":"emp","_id":"11"}}
{"name":"tom", "age":27}
{"update":{"_index":"zhouls","_type":"emp", "_id":"2"}}
{"doc":{"age" :22}}
{"delete":{"_index":"zhouls","_type":"emp","_id":"1"}}
在$ES_HOME目录下，执行下面命令
curl -PUT '192.168.80.200:9200/_bulk' --data-binary @request;
或
curl -XPOST '192.168.80.200:9200/_bulk' --data-binary @request;
[hadoop@djt002 elasticsearch-2.4.3]$ curl -PUT '192.168.80.200:9200/_bulk' --data-binary @request;
{"took":123,"errors":true,"items":[{"index":{"_index":"zhouls","_type":"emp","_id":"10","_version":1,"_shards":{"total":2,"successful":1,"failed":0},"status":201}},{"index":{"_index":"zhouls","_type":"emp","_id":"11","_version":1,"_shards":{"total":2,"successful":1,"failed":0},"status":201}},{"update":{"_index":"zhouls","_type":"emp","_id":"2","status":404,"error":{"type":"document_missing_exception","reason":"[emp][2]: document missing","index":"zhouls","shard":"-1"}}},{"delete":{"_index":"zhouls","_type":"emp","_id":"1","_version":1,"_shards":{"total":2,"successful":1,"failed":0},"status":404,"found":false}}]}[hadoop@djt002 elasticsearch-2.4.3]$
之后，再查看下。
[hadoop@djt002 elasticsearch-2.4.3]$ curl -XGET 'http://192.168.80.200:9200/zhouls/emp/1?pretty'
{
"_index" : "zhouls",
"_type" : "emp",
"_id" : "1",
"found" : false
}
[hadoop@djt002 elasticsearch-2.4.3]$ curl -XGET 'http://192.168.80.200:9200/zhouls/emp/2?pretty'
{
"_index" : "zhouls",
"_type" : "emp",
"_id" : "2",
"found" : false
}
[hadoop@djt002 elasticsearch-2.4.3]$ curl -XGET 'http://192.168.80.200:9200/zhouls/emp/11?pretty'
{
"_index" : "zhouls",
"_type" : "emp",
"_id" : "11",
"_version" : 4,
"found" : true,
"_source" : {
"name" : "tom",
"age" : 27
}
}
[hadoop@djt002 elasticsearch-2.4.3]$ curl -XGET 'http://192.168.80.200:9200/zhouls/emp/10?pretty'
{
"_index" : "zhouls",
"_type" : "emp",
"_id" : "10",
"_version" : 4,
"found" : true,
"_source" : {
"name" : "jack",
"age" : 18
}
}
（3） bulk请求可以在URL中声明/_index 或者/_index/_type
这个，自行去测试！
官网
https://www.elastic.co/guide/en/elasticsearch/reference/current/docs-bulk.html
